The present invention generally relates to a drag conveyor, which can be a cable or chain conveyor. Such conveyors are known and generally include an outer tube through which an endless cable, chain or other traction element is drawn. Disks of flights are attached to the traction element at periodic intervals and, by moving the traction element in a transport direction, powdered or granular material that is fed through an opening in the tube into spaces between disks is carried forward through the tube to an unloading point where the tube is open in a bottom area so that the material can be discharged.
Such conveyors are useful for moving powdered or granular materials without damaging or breaking down the material which can occur with augur-type tube conveyors. Since the material is merely pushed along the inside of the tube by the disks which are attached to the conveyor traction element, the likelihood of damage to the granular material being transported is greatly reduced.
In order to maintain smooth operation, the traction element needs to be maintained at a predetermined tension or within a predefined range. Tensioning is typically accomplished by manually adjusting the position of a return sprocket or pulley for the traction element. However, this requires periodic maintenance due to stretching of the traction element, and does not account for the influence of the goods being conveyed.